Cisco
Cisco IOS: vulnerabilities and CVEs
Cisco IOS has 624 published vulnerabilities, 3 of them in the last 12 months. 8 are rated critical and 39 are listed by CISA as actively exploited.
CVEs624
Last 12 months3
Critical8
Actively exploited39
All vulnerabilities in the catalogue →⭐ Follow this technology
🔴 Actively exploited (CISA KEV)
| CVE | Severity | EPSS | Active exploitation | Published | Description |
|---|---|---|---|---|---|
| CVE-2008-4128 | High (8.1) | 34% | ⚠ Active exploitation | Sep 18, 2008 | Multiple cross-site request forgery (CSRF) vulnerabilities in the HTTP Administration component in Cisco IOS 12.4 on the 871 Integrated Services Router allow remote attackers to execute arbitrary commands via (1) a… |
| CVE-2025-20352 | High (7.7) | 39% | ⚠ Active exploitation | Sep 24, 2025 | A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a… |
| CVE-2023-20109 | Medium (6.6) | 2.5% | ⚠ Active exploitation | Sep 27, 2023 | A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group… |
| CVE-2004-1464 | Medium (5.9) | 4.8% | ⚠ Active exploitation | Dec 31, 2004 | Cisco IOS 12.2(15) and earlier allows remote attackers to cause a denial of service (refused VTY (virtual terminal) connections), via a crafted TCP connection to the Telnet or reverse Telnet port. |
| CVE-2016-6415 | High (7.5) | 88% | ⚠ Active exploitation | Sep 19, 2016 | The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, and PIX before 7.0 allows remote attackers to obtain sensitive… |
| CVE-2017-6742 | High (8.8) | 21% | ⚠ Active exploitation | Jul 17, 2017 | The vulnerability is due to a buffer overflow in the affected code area. The vulnerability affects all versions of SNMP (versions 1, 2c, and 3). The attacker must know the SNMP read only community string (SNMP version… |
| CVE-2017-3881 | Critical (9.8) | 99% | ⚠ Active exploitation | Mar 17, 2017 | A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely… |
| CVE-2017-6743 | High (8.8) | 11% | ⚠ Active exploitation | Jul 17, 2017 | The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected… |
| CVE-2017-6663 | Medium (6.5) | 2.1% | ⚠ Active exploitation | Aug 7, 2017 | A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting… |
| CVE-2017-6627 | High (7.5) | 6.2% | ⚠ Active exploitation | Sep 7, 2017 | A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP… |
| CVE-2017-12237 | High (7.5) | 7.1% | ⚠ Active exploitation | Sep 29, 2017 | A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS 15.0 through 15.6 and Cisco IOS XE 3.5 through 16.5 could allow an unauthenticated, remote attacker to cause high CPU utilization,… |
| CVE-2017-12231 | High (7.5) | 7.1% | ⚠ Active exploitation | Sep 29, 2017 | A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an… |
| CVE-2017-12240 | Critical (9.8) | 14% | ⚠ Active exploitation | Sep 29, 2017 | The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an… |
| CVE-2017-12233 | High (7.5) | 7.1% | ⚠ Active exploitation | Sep 29, 2017 | Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload,… |
| CVE-2017-12235 | High (7.5) | 7.1% | ⚠ Active exploitation | Sep 29, 2017 | A vulnerability in the implementation of the PROFINET Discovery and Configuration Protocol (PN-DCP) for Cisco IOS 12.2 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload,… |
| CVE-2017-12234 | High (7.5) | 7.1% | ⚠ Active exploitation | Sep 29, 2017 | Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload,… |
| CVE-2017-12232 | Medium (6.5) | 2.2% | ⚠ Active exploitation | Sep 29, 2017 | A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an… |
| CVE-2017-12238 | Medium (6.5) | 2.0% | ⚠ Active exploitation | Sep 29, 2017 | A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a C6800-16P10G or… |
| CVE-2018-0172 | High (8.6) | 7.8% | ⚠ Active exploitation | Mar 28, 2018 | A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a… |
| CVE-2018-0158 | High (8.6) | 7.2% | ⚠ Active exploitation | Mar 28, 2018 | A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected… |
Latest vulnerabilities
| CVE | Severity | EPSS | Active exploitation | Published | Description |
|---|---|---|---|---|---|
| CVE-2026-20301 | High (8.6) | 0.57% | — | Aug 5, 2026 | A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as the External Client protocol, of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to… |
| CVE-2026-20125 | High (7.7) | 0.28% | — | Mar 25, 2026 | A vulnerability in the HTTP Server feature of Cisco IOS Software and Cisco IOS XE Software Release 3E could allow an authenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a… |
| CVE-2026-20012 | High (8.6) | 0.35% | — | Mar 25, 2026 | A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat… |
| CVE-2025-20363 | Critical (9) | 6.9% | — | Sep 25, 2025 | A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR… |
| CVE-2025-20352 | High (7.7) | 39% | ⚠ Active exploitation | Sep 24, 2025 | A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a… |
| CVE-2025-20327 | High (7.7) | 0.39% | — | Sep 24, 2025 | A vulnerability in the web UI of Cisco IOS Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to… |
| CVE-2025-20160 | High (8.1) | 0.43% | — | Sep 24, 2025 | A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This… |
| CVE-2025-20149 | Medium (6.5) | 0.12% | — | Sep 24, 2025 | A vulnerability in the CLI of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS)… |
| CVE-2025-20253 | High (8.6) | 0.47% | — | Aug 14, 2025 | A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting… |
| CVE-2025-20239 | High (8.6) | 0.62% | — | Aug 14, 2025 | A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and Secure Firewall Threat Defense (FTD)… |
| CVE-2025-20225 | Medium (5.8) | 0.71% | — | Aug 14, 2025 | A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and Secure Firewall Threat Defense (FTD)… |
| CVE-2025-20191 | High (7.4) | 0.24% | — | May 7, 2025 | A vulnerability in the Switch Integrated Security Features (SISF) of Cisco IOS Software, Cisco IOS XE Software, Cisco NX-OS Software, and Cisco Wireless LAN Controller (WLC) AireOS Software could allow an… |
| CVE-2025-20181 | Medium (6.8) | 0.19% | — | May 7, 2025 | A vulnerability in Cisco IOS Software for Cisco Catalyst 2960X, 2960XR, 2960CX, and 3560CX Series Switches could allow an authenticated, local attacker with privilege level 15 or an unauthenticated attacker with… |
| CVE-2025-20154 | High (8.6) | 0.51% | — | May 7, 2025 | A vulnerability in the Two-Way Active Measurement Protocol (TWAMP) server feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the affected device to reload,… |
| CVE-2025-20137 | Medium (4.7) | 0.27% | — | May 7, 2025 | A vulnerability in the access control list (ACL) programming of Cisco IOS Software that is running on Cisco Catalyst 1000 Switches and Cisco Catalyst 2960L Switches could allow an unauthenticated, remote attacker to… |
| CVE-2025-20176 | High (7.7) | 0.76% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20175 | High (7.7) | 0.76% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20174 | High (7.7) | 0.76% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20173 | High (7.7) | 0.76% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20172 | High (7.7) | 0.76% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20171 | High (7.7) | 0.78% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20170 | High (7.7) | 0.78% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2025-20169 | High (7.7) | 0.78% | — | Feb 5, 2025 | A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. |
| CVE-2024-20465 | Medium (5.8) | 0.42% | — | Sep 25, 2024 | A vulnerability in the access control list (ACL) programming of Cisco IOS Software running on Cisco Industrial Ethernet 4000, 4010, and 5000 Series Switches could allow an unauthenticated, remote attacker to bypass a… |
| CVE-2024-20433 | High (7.5) | 0.63% | — | Sep 25, 2024 | A vulnerability in the Resource Reservation Protocol (RSVP) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly,… |
| CVE-2024-20414 | Medium (6.5) | 0.26% | — | Sep 25, 2024 | A vulnerability in the web UI feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system through… |
| CVE-2024-20308 | High (7.5) | 0.80% | — | Mar 27, 2024 | A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap underflow, resulting in an affected device reloading. This… |
| CVE-2024-20307 | High (7.5) | 0.73% | — | Mar 27, 2024 | A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap overflow, resulting in an affected device reloading. This… |
| CVE-2024-20312 | High (7.4) | 0.26% | — | Mar 27, 2024 | A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS)… |
| CVE-2024-20311 | High (7.5) | 0.80% | — | Mar 27, 2024 | A vulnerability in the Locator ID Separation Protocol (LISP) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This… |
🎯 How it gets exploited (ATT&CK techniques)
Number of CVEs of this technology mapped to each exploitation or primary-impact technique.
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